Suspension for a ploughshare assembly of a grading machine

ABSTRACT

A soil tilling machine comprising a ploughshare assembly supported on a supporting member between the wheel axles for rotation, and capable of being locked in an adjusted angular position in relation to the longitudinal axis of the machine. The supporting member is pivotally attached at its front end to a frame of the machine so as to be capable of being adjusted in elevation and in lateral tilted position by means of hydraulic cylinders which are connected to the free rear end of the supporting member at laterally offset sides thereof and to a suspension body which is longitudinally displaceable on the frame.

ASSEMBLY OF A GRADING MACHINE Helmut Brodersen, Angelholz, Germany Assignee: Maschinenbau Ulm GmbI-l Filed: Mar. 2, 1972 Appl. No.: 231,173

Inventor:

Foreign Application Priority Data Mar. 3, 1971 Germany P 21 [0 200.1

US. Cl. 172/789, 172/793 Int. Cl. C02f 3/12- Field at Search; 172/781, 780, 789, 1 172/791, 793, 779, 795

References Cited UNITED STATES PATENTS Johnson et al....l 172/789 United States Patent 11 1 1111 3,763,938 Brodersen I Oct. 9, 1973 [54] SUSPENSION FOR A PLOUGHSHARE 1,769,682 7/1930 Faverty 172 793 x Primary Examiner-Robert E. Pulfrey Assistant Examiner-Stephen C. Pellegrino Attorney-Eric [-1. Waters et a],

[57] ABSTRACT A soil tilling machine comprising a ploughshare assembly supported on a supporting member between 1 the wheel axles for rotation, and capable of being locked in an adjusted angular position in relation to the longitudinal axis of the machine. The supporting member is pivotally attached at its front end to a frame of the machine so as to be capable of being adjusted in elevation and in lateral tilted position by 7 means of hydraulic cylinders which are connected to the free rear end of the supporting; member at laterally offset sides thereof and to a suspension body which is longitudinally displaceable on the frame.

11 Claims, 2 Drawing Figures SUSPENSION FOR A PLOUGHSHARE ASSEMBLY OF A GRADING MACHINE BACKGROUND a. Field of the Invention The invention relates to a suspension for a ploughshare assembly of a soil tilling and levelling machine constituted as a grader.

b. Prior Art It is known to support the ploughshare assembly between the axles of a grader on a supporting arm such that the ploughshare assembly is rotatable and capable of being fixed in adjustable angular positions in relation to the longitudinal axis of the grader. The supporting arm is rotatably attached, preferably at the front end of the girder or frame of the grader, by means of a joint, and is capable of being adjusted, as regards elevation and lateral position, by means of hydraulic cylinders which are connected to the free end of the supporting arm and are attached to the girder on mutually opposite sides thereof.

The versatility of utilization of such graders and the quality of the surfaces produced thereby are to a large degree determined by the accuracy and the multiplicity of the possibilities of adjustment of the ploughshare assembly. ln the conventional graders of the above kind, the lateral and elevational adjustments of the ploughshare assembly are accomplished by means of hydraulic cylinders which are arranged on both sides of the girder, each of said cylinders engaging one side of the free end of the supporting arm, which supports the ploughshare assembly. lf it is desired to achieve lateral positions of the ploughshare assembly outside the wheel track of the grader, the hydraulic cylinders must have a very long stroke and, consequently, they project on both sides of the girder considerably in the upward direction. In order to give these long-stroke hydraulic cylinders the necessary freedom of pivoting and movement, they are tiltably attached to both ends of a transverse girder which is attached to the longitudinal girder of the grader. in order to achieve the positions of the ploughshare assembly which are located outside the wheel track of the grader, the transverse girders of conventional embodiments are tilted about the longitudinal girders by appropriate means, in such a manner that the points of attachment travel along a circular or elliptical path about the girder, so that the points of attachment are located above or below the girder. The magnitude and awkwardness of the tiltable transverse girder as well as the point of attachment also impair the range of vision of the operator.

SUMMARY OF THE INVENTION It is an object of the invention to provide a suspen: sion for a ploughshare assembly in such a manner that many positions of the ploughshare assembly can be achieved, and, in particular, such positions which are necessary in order to be able to reach surfaces to be worked which are located outside the wheel track of the grading machine, but simultaneously to avoid a tiltable transverse girder with its operational difficulties, and to improve the visibility conditions.

To achieve this objective, a suspension and adjustment device is provided which, moreover is compact and is located at such a point of the grader and the girder thereof, which results in the best possible conditions of vision. I

ln order to meet this objective, there is contemplated a suspension for a ploughshare of the above mentioned kind in a grader, in which hydraulic cylinders are pivotably attached to a suspension body which is displaceable in the direction of the longitudinal axis of the grader and is adjustably fixable in position, said suspension body being attached to the girder or to the body of the grader. This construction of the suspension permits the use of relatively small hydraulic cylinders for actuation of the ploughshare, said cylinders having short strokes, i.e. shorter than would be necessary for the entire displacement of the ploughshare assembly itself, since at least a portion of the adjustment of the elevation of the ploughshare assembly is achieved by a horizontal movement of the suspension body. The suspension is so constructed that no suspension or adjustment devices project above the girder of the grader, so that the visibility of the operator is not impaired. Movement of the suspension body along the longitudinal girder in the directionof the supporting member attached at the front end of the girder, results in lifting of the free end of the supporting member which supports the ploughshare assembly.

ln an advantageous embodiment of the invention, the suspension body is supported in a guide on the girder or frame of the grader, the suspension body is displaceable and adjustable therein by means of a adjustment device which is located between the suspension body and the girder and extends approximately in the longitudinal direction of the girder. In a particularly advantageousembodiment, since there is already provided a hydraulic device for the hydraulic cylinders for actuation of the ploughshare, the adjustment device is constructed as a hydraulic cylinder attached to the suspension body and to the girder.

A particularly advantageous embodiment, which is free of undesirable tilting moments is obtained by connecting the hydraulic cylinders, which are attached to the supporting member on both sides of the longitudi nal axis of the machine, to the suspension body in a common swivel joint, the hydraulic cylinders thereby forming the lateral sides of a triangle extending transversely of the longitudinal axis of the machine, the base of the triangle being formed by the free end of the supporting member. The inclination of the ploughshare assembly transversely to the longitudinal axis of the machine is achieved by differential extension of the hydraulic cylinders attached to the support member. The adjustment of the elevational position of the ploughshare assembly is achieved on the one hand by symmetrical extension or retraction of the hydraulic cylinders and, on the other hand, by the longitudinal adjustment of the position of the suspension body in relation to the girder. As a result of the fact that both hydraulic cylinders connected to the lateral sides of the support member, are connected to the suspension body at a common point, preferably a common swivel joint, it is avoided that additional tilting or overturning moments are applied to the suspension body, said tilting moments resulting from the various adjustment positions of the hydraulic cylinders, and which would invariably result if the points of attachment of the individual hydraulic cylinders were offset from the common swivel joint.

ln order to fix both the adjusted position of the hydraulic cylinders for the ploughshare and the suspension body, and thus of the ploughshare assembly, an additional cylinder is connected between the free end of the supporting member, which supports the ploughshare assembly, and the frame of the machine, extending transversely to the hydraulic cylinders attached to the suspension body, said additional cylinder being mounted in universal joints at its end attached to the supporting member as well as at its end attached to the frame of the machine. The additional cylinder has a stabilizing function. lts point of attachment to the frame is advantageously displaceable and adjustable in a direction perpendicular to the longitudinal axis of the grader.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic side elevation view of a grading machine in which the suspension of the ploughshare assembly is according to the invention; and

FIG. 2 is a top plan view of the machine.

DETAILED DESCRlPTlON Referring to the drawing, therein is seen a grader having a frame whose central part between the axles carrying front steerable wheels 1 and rear wheels 2 is constituted as a bridge girder 3. At the front end of the girder 3, there is provided, in front of the front axle 4, a suspension device for additional working tools e.g. a shield or blade 5 for earth moving operations. At the rear of the frame, there is mounted a driving motor (not shown) and a cabin 7 for an operator. Below the girder 3, between the front wheels 1 and the rear wheels 2, there is provided a levelling ploughshare assembly 8 with the suspension according to the invention. A supporting member 9 which is triangular in outline in top plan view and which supports the ploughshare assembly 8 is suspended in a ball-and-socket joint 11 at the front portion 10 of the frame. The member 9 is pivotable in joint 11 about a transverse axis so as to be pivotable in an up and down manner in a vertical plane passing through the longitudinal axis of the grader, the member 9 also being pivotable in joint 11 about the longitudinal axis so as to be laterally tiltable. The member is provided in the region of its free rear end 12 (the base of the triangle) with a rotatable ring 13, to which the ploughshare assembly 8 is fastened. By rotation of ring 13 in lockable clamps 1311 (one being visible in FIG. 1) the horizontal angular position of assembly 8 can be adjusted in relation to the longitudinal axis of the grader. At the free end 12 of the supporting member 9, approximately in the region of the vertices of the triangle, there are attached hydraulic cylinders 14, 15 by means of ball-and-socket joints. The hydraulic cylinders are attached at their other ends to a suspension body 16 by means of ball-and-socket joints. The suspension body 16 is located just below the lower surface of the girder 3 and it is guidably displaceable in the longitudinal direction of the girder (along the central axis of the grader), by means of a guide 16a. The adjustment of the position of suspension body 16 in the longitudinal direction of the grader is effected by an adjusting device, which comprises a hydraulic adjustment cylinder 17. For stabilization of the supporting member 9 with the ploughshare assembly in its various positions, a further hydraulic cylinder 18 is provided, the cylinder 18 having one of its ends attached to the free end 12 of the supporting member 9 and its other end attached at 19 to the frame 6. The point of support 19 in the frame 6 is adjustable in the directions of the arrows 20 in FIG. 2, so that allowance can be made for various requirements. A continuous readjustment capability of the point of support 19 is not necessarily required.

The hydraulic cylinders 14, 15 position the member 9 as regards its angular attitude relative to both the longitudinal and transverse axes passing through joint 11. By differential extensions of the cylinders 14 and 15, the ploughshare assembly can be given an angle of inclination in the vertical direction up to a substantially vertical position of the ploughshare assembly 8. In order to avoid transmission of unnecessary tilting moments to the suspension body 16, the hydraulic cylinders 14 and 15 are attached to the suspension body 16 in such a manner that the application of force from both cylinders occurs substantially at the same point on the suspension body.

The lifting and lowering operations of the supporting member 9, and thereby of the ploughshare assembly 8, can be accomplished, on the one hand, by synchronized extension of the hydraulic cylinders 14 and 15 causing displacement of the suspension body 16 in the longitudinal direction of the grading machine. There is shown in FIG. 1 in broken lines position 16 of the suspension body. When the suspension body 16 is moved to position 16' by means of the cylinder 17, the supporting member 9 is lifted to the position 9' shown in broken lines.

The adjustment of the ploughshare assembly 8 is, in general, achieved solely by the hydraulic cylinders 14, 15 and 17, the latter serving as a readjustment device for the suspension body 16. The hydraulic cylinder 18 serves in general the purpose of stabilized fixation of the assembly.

What is claimed is:

l. A soil tilling machine having a frame with a longitudinal axis, and front and rear axles with wheels thereon supported from the frame, said machine comprising a supporting member having a front end pivotably connected to the frame,a free rear end which can be moved up and down and tilted laterally when the supporting member is pivotably moved about the frame, a ploughshare assembly supported by said supporting member at a location between the axles, a pair of hydraulic cylinders pivotably connected to the supporting member at transversely offset locations to tilt the supporting member and the ploughshare assembly therewith when the cylinders are operated differentially and to raise and lower the free rear end of the supporting member when the cylinders are operated in synchronism, a suspension body, and means supporting the suspension body from the frame for longitudinal movement with respect to said frame, said cylinders being pivotably coupled to said suspension body.

2. A machine as claimed in claim 1 comprising adjustment means connected to said suspension body and said frame for providing longitudinal displacement of the suspension body.

3. A machine as claimed in claim 2 wherein said adjustment means comprises a hydraulic cylinder oriented in the longitudinal directionof the frame.

4. A machine as claimed in claim 2 comprising a common pivot connecting said cylinders to said suspension body.

5. A machine as claimed in claim 2 wherein said supporting member is of triangular shape with side arms connected together at said front end and diverting rearwardly, and a transverse member connected to said side arms to form the base of the triangular member.

6. A machine as claimed in claim 5 wherein said cylinders are connected to said triangular member proximate the respective opposite ends of the base.

7. A machine as claimed in claim 4 wherein said pair of hydraulic cylinders connected to the supporting member form with the rear end of the supporting member a triangle.

8. A machine as claimed in claim 7 comprising a further hydraulic cylinder connected to said frame and said supporting member.

9. A machine as claimed in claim 8 wherein said further hydraulic cylinder is connected to the supporting member at the rear end thereof and extends transversely with respect to said pair of hydraulic cylinders,

said further hydraulic cylinder being connected to said frame and the supporting member by respective universal joints.

10. A machine as claimed in claim 9 comprising means attaching the further hydraulic cylinder to the frame for adjustment in a direction perpendicular to the longitudinal axis of the frame.

ber. 

1. A soil tilling machine having a frame with a longitudinal axis, and front and rear axles with wheels thereon supported from the frame, said machine comprising a supporting member having a front end pivotably connected to the frame,a free rear end which can be moved up and down and tilted laterally when the supporting member is pivotably moved about the frame, a ploughshare assembly supported by said supporting member at a location between the axles, a pair of hydraulic cylinders pivotably connected to the supporting member at transversely offset locations to tilt the supporting member and the ploughshare assembly therewith when the cylinders are operated differentially and to raise and lower the free rear end of the supporting member when the cylinders are operated in synchronism, a suspension body, and means supporting the suspension body from the frame for longitudinal movement with respect to said frame, said cylinders being pivotably coupled to said suspension body.
 2. A machine as claimed in claim 1 comprising adjustment means connected to said suspension body and said frame for providing longitudinal displacement of the suspension body.
 3. A machine as claimed in claim 2 wherein said adjustment means comprises a hydraulic cylinder oriented in the longitudinal direction of the frame.
 4. A machine as claimed in claim 2 comprising a common pivot connecting said cylinders to said suspension body.
 5. A machine as claimed in claim 2 wherein said supporting member is of triangular shape with side arms connected together at said front end and diverting rearwardly, and a transverse member connected to said side arms to form the base of the triangular member.
 6. A machine as claimed in claim 5 wherein said cylinders are connected to said triangular member proximate the respective opposite ends of the base.
 7. A machine as claimed in claim 4 wherein said pair of hydraulic cylinders connected to the supporting member form with the rear end of the supporting member a triangle.
 8. A machine as claimed in claim 7 comprising a further hydraulic cylinder connected to said frame and said supporting member.
 9. A machine as claimed in claim 8 wherein said further hydraulic cylinder is connected to the supporting member at the rear end thereof and extends transversely with respect to said pair of hydraulic cylinders, said further hydraulic cylinder being connected to said frame and the supporting member by respective universal joints.
 10. A machine as claimed in claim 9 comprising means attaching the further hydraulic cylinder to the frame for adjustment in a direction perpendicular to the longitudinal axis of the frame.
 11. A machine as claimed in claim 1 wherein said means which supports the suspension body comprises longitudinal guides secured to said frame therebeneath, said cylinders being suspended from said suspension body below the frame and undergoing tilting when the suspension body travels in said guides to cause raising and lowering of said rear end of the supporting member. 